Apparatus for mixing volatile liquid with nonvolatile material

ABSTRACT

An apparatus for mixing and feeding a volatile liquid, such as liquid ammonia, with a nonvolatile material, such as a fabric finisher; the method comprising the steps of feeding the liquid to a mixing vessel and, by volatilizing a portion of the liquid, cooling the vessel and, while continuing to feed the liquid and after the cooled liquid has reached a predetermined level in the vessel, adding to the liquid a measured amount of nonvolatile material, continuing the liquid feed until the liquid level reaches the measured amount, agitating the liquid and material and, as the liquid volatilizes, adding additional of such liquid to maintain the liquid level at the measured amount; the apparatus comprising a mixing tank having a cover, a coolant coil in the mixing tank, first feed means having a valve for feeding a volatile liquid to the tank, second feed means having a valve for feeding a nonvolatile material to the tank, a float and switch in the tank for controlling the liquid feed valve, a float and switch in the tank for controlling the nonvolatile material feed valve, a discharge line for discharging the mixed material from the tank to a trough in a fabric treatment chamber, a valve in the discharge line, electrical means for opening and closing the valve in the discharge line and for closing the liquid feed valve when the discharge valve is open and for closing such liquid feed valve when the discharge valve is open, the floats in the tank opening and closing the liquid feed and material feed valves when the liquid in the tank is at pre-set levels.

United States Patent [191 Troope [451 May 27, 1975 1 APPARATUS FORMIXING VOLATILE LIQUID WITH NONVOLATILE MATERIAL Walter S. Troupe,Latham, N.Y.

[73] Assignee: Cluett, Peabody & Co., Inc., New

York, NY.

[22] Filed: Mar. 9, 1972 [21] Appl. No.1 234,442

Related U.S. Application Data [62] Division of Ser. No. 854,542, Sept.2, 1969,

[75] Inventor:

abandoned.

52 U.S. c1. ..137/391;259/4;259/7; 259/65 511 Int. Cl B0lf 15/04 581Field ofSearch 259/4, 5,6,7, 8, 18,

Primary ExaminerRobert W. Jenkins [57] ABSTRACT An apparatus for mixingand feeding a volatile liquid,

such as liquid ammonia, with a nonvolatile material, such as a fabricfinisher; the method comprising the steps of feeding the liquid to amixing vessel and, by volatilizing a portion of the liquid, cooling thevessel and, while continuing to feed the liquid and after the cooledliquid has reached a predetermined level in the vessel, adding to theliquid a measured amount of nonvolatile material, continuing the liquidfeed until the liquid level reaches the measured amount, agitating theliquid and material and, as the liquid volatilizes, adding additional ofsuch liquid to maintain the liquid level at the measured amount; theapparatus comprising a mixing tank having a cover, a coolant coil in themixing tank, first feed means having a valve for feeding a volatileliquid to the tank, second feed means having a valve for feeding anonvolatile material to the tank, a float and switch in thetank forcontrolling the liquid feed valve, a float and switch in the tank forcontrolling the nonvolatile material feed valve, a discharge line fordischarging the mixed material from the tank to a trough in a fabrictreatment chamber, a valve in the discharge line, electrical means foropening and closing the valve in the discharge line and for closing theliquid feed valve when the discharge valve is open and for closing suchliquid feed valve when the discharge valve is open, the floats in thetank opening and closing the liquid feed and material feed valves whenthe liquid in the tank is at pre-set levels.

9 Claims, 1 Drawing Figure APPARATUS FOR MIXING VOLATILE LIQUID WITHNONVOLATILE MATERIAL CROSS REFERENCE This application is a divisionalapplication with respect to my copending application Ser. No. 854,542,filed Sept. 2, 1969, now abandoned.

This invention relates to a method and apparatus for mixing highlyvolatile liquid with nonvolatile materials for the treatment of fabricand, more particularly, to such a method and apparatus for mixing liquidammonia with resins, dyes or other finishing agents for the treatment offabric to make such treated fabric crease and wrinkle resistant.

In U.S. Pat. application Ser. No. 834,730, filed June 19, 1969, there isshown and described apparatus for treating fabric with ammonia orammonia with additives, such as resin. The fabric is fed into a chamberhaving an ammonia saturated atmosphere and immersed in a troughcontaining liquid ammonia or liquid ammonia and additives. In thetrough, the fabric is saturated. After the fabric is fed out of thetrough, the ammonia is driven off.

Liquid ammonia, at atmospheric conditions, is highly volatile and isusually stored under pressure and, in storage under pressure, may berefrigerated. In the apparatus of the aforementioned application, thetreatment cabinet is insulated. The ammonia vaporized therein reducesthe temperature of the cabinet atmosphere to a relatively lowtemperature. Thus, while the volume of liquid ammonia in the fabricimmersion trough is relatively low, the relatively low temperature ofthe cabinet atmosphere and the ammonia vapor saturated condition of suchatmosphere prevents significant vaporization of the liquid ammonia fromthe immersion trough while fabric is being treated. Thus, because theliquid ammonia in the ammonia immersion trough in the treatment chamberdoes not vaporize, the proportion of nonvolatile additives, such asresin, in the liquid ammonia in the immersion trough can be maintainedat a substantially constant level. This is important because, if thereis substantial variation in the additive content of the liquid ammoniaas the fabric is passed therethrough, the amount of additive, such asresin, deposited on such fabric will vary, resulting in markedvariations in the properties of the fabric after treatment.

The addition of the additives to the liquid ammonia, and the uniformdispersion of such additives therein, is of substantial importance tothe depositing of the additives on the fabric in a uniform manner. Thus,in order that the additive, such as dye, resin, or other fabric finishermight be added to the liquid ammonia in uniform quantity and might beuniformly dispersed in the liquid ammonia, it is desirable to make suchaddition to the liquid ammonia and disperse the additive therein beforethe mixture is fed to the fabric immersion trough. This is accomplished,in the instant invention, by mixing tanks located outside of thetreatment cabinet. Such tanks are connected to the immersion trough sothat, as the liquid ammonia-additive mixture is required in theimmersion trough, it is fed to the trough automatically from the mixturetank.

In the apparatus of the instant invention, two tanks are provided. Whilethe liquid ammonia-additive mixture is being fed from one tank to thefabric immersion trough in the treatment chamber, the other tank isbeing charged with liquid ammonia and additive, such as resin, and theadditive is being dispersed in the liquid ammonia. The liquid ammonia,as it may vaporize from the mixing tank during charging and dispersionin such tank, is automatically replaced with liquid ammonia to maintainthe liquid ammonia-additive proportion at a constant level until suchtime as the mixture in such tank is fed to the immersion trough in thetreatment chamber. Thus, in the process and apparatus of the instantinvention, the immersion trough in the treatment chamber is constantlysupplied with a liquid ammoniaadditive mixture in which the additivecontent and additive dispersion is maintained at a constant uniformlevel.

The invention and advantages thereof will be better understood from thefollowing description and appended drawing.

Referring to the drawing, the apparatus of the instant inventionincludes treatment cabinet, generally designated 2, into which fabric 4is fed through seal, generally designated 6, and around roll 8 intoimmersion trough, generally designated 10, all as more particularlydescribed in the afore-mentioned U.S. patent applications.

For purposes more fully described later herein, trough 10 has, near itsupper level, float 12 connected to micro-switch 14. Micro-switch 14 isconnected to solenoid 16 of valve 18 in supply line 20. Supply line 20is connected to supply line 22 of trough 10. Supply line 20 has manualvalves 24, 25 and supply line 22 has a manual valve 26. During normaloperation, manual valve 24 is opened and valve 26 is closed. During shutdown or when itmay be desired to empty immersion trough 10, manual valve24 in supply line 20 is closed and valve 26 in supply 22 is opened.

Mixing tank, generally designated 30, is connected to supply line 20through connecting line 32. Valve 34, controlled by solenoid 36, andmanual valve 38 are in connecting line 32 between mixing tank 30 andsupply line 20. Intermediate valves 34, 38 dump line 40, having manualvalve 42, is connected to line 32. The upper end of mixing tank 30 isconnected, by vent line 44, to duct 46 connected to the interior ofchamber 2 and by vent line 45 to duct 47. Duct 47 is connected to thestack, not shown, of chamber 2. Flapper valve 50 at the junction of ventlines 44, 45 vents tank 30 to either duct 46 and chamber 2 or to duct 47and the stack, not shown.

A second mixing tank, generally designated 54, is connected to supplyline 20 through connecting line 56. Valve 58, controlled by solenoid 60and manual valve 62 are in connecting line 56 between mixing tank 54 andsupply line 20. Intermediate valves 58, 62, dump line 64, having manualvalve 66, is connected to line 56. The upper end of mixing tank 54 isconnected, by vent line 68, to duct 46 and duct 47. Flapper valve 69 atthe junction of line 68 and duct 46, selectively vents tank 54 to duct46 and chamber 2 or to duct 47 and the stack, not shown.

Mixing tanks 30, 54 are identical and each have identical liquid ammoniaand resin feeds, feed controls and control circuitry. Hence, in thefollowing description, one of the mixing tanks and the control circuitrywill be described, it being understood that the other tank includes thesame elements.

Mixing tank 30 includes mixing chamber 70 of heat insulating materialsuch as, for example, inner and outer metal shells filled, intermediatethe shells, with a non-heat conducted material. Cover 72, preferablyremovable, has a downwardly extending flange 74 and inwardly extendingflange 76 which, with seal 78, forms a vapor-tight seal at the upper endof mixing chamber 70. Mixer 80, having shaft 82 and mixing impeller 84,is mounted on cover 72. Coolant coil 86, fed with a coolant from acondenser and compressor, not shown, is mounted in mixing chamber 70around the periphery thereof. Additive supply line 90, having valve 92,controlled by solenoid 94, and liquid ammonia line 96, having valve 98,controlled by solenoid 100, extend downwardly into mixing chamber 70and, as later described, feed liquid ammonia and additive into tank 30.Float 102 is connected to micro-switch 104 and microswitch 104 isconnected, through lead 106, and timer 110 to solenoid 94. Float 112 isconnected to microswitch 114 and micro-switch 114 is connected tosolenoid 100. Solenoid switch 116 is normally closed and is opened whenswitch 118 in line 120, connected to solenoid 36, is closed for reasonslater explained herein.

in the operation of chamber 2 for the treatment of fabric 4 by immersingand saturating the fabric to be treated with ammonia, trough may besupplied with liquid ammonia through supply lines 20, 22 or with liquidammonia-additive mixture. When liquid ammonia, alone, is employed,valves 24 and 25 in supply line are opened and manual valves 26, 38, 62,in supply line 22 and connecting lines 32, 56, respectively, are closed.When the fabric is to be treated with liquid ammonia-additive mixture,manual valve in supply line 20 is closed and manual valves 38 and 62 inconnecting lines 32, 56, respectively, are opened.

The following description of the operation of the apparatus and methodof the instant invention is for treatment of the fabric in immersiontrough 10 with liquid ammonia-additive mixture. Such additive may beresins, dyes or other fabric finishes. Hence, manual valve 25 in supplyline 20 and manual valve 26 in supply line 22 are closed and manualvalve 24 in supply line 20 and manual valves 38, 62 in connecting lines32, 56 are open. Prior to the start of such treatment, one of the mixingtanks has been charged with liquid ammonia and additive and suchadditive has been dispersed therein, in the manner hereinafterdescribed. The various switches connecting the electrical controls to asource of power, not shown, have been closed and switch 118 onelectrical lead 120 to solenoid 36 has been closed, opening solenoidswitch 116. Solenoid 36 opens valve 34 and the liquid ammonia-additivemixture in such charged tank is fed through the connecting line intosupply line 20. As the level of liquid ammoniaadditive mixture in trough10 drops, float 12 closes, switch 14 actuates solenoid 16 and opensvalve 18, allowing the liquid ammonia-additive mixture from the chargedmixing tank to feed through supply lines 20, 22 into trough 10. As thelevel of the liquid in immersion trough 10 increases float 12 opensswitch 14, deenergizes solenoid 16 and closes valve 18. This operationcontinues until the mixing tank charged with liquid ammonia-additivemixture on stream is empty. The second tank is charged, in the mannerhereinafter described, while the first tank is on stream and is put onstream when the first tank is emptied. The empty mixing tank is takenoff stream and re-charged.

In the method, or process, of the instant invention for mixing ameasured amount of nonvolatile material, such as, resins, dyes, or otherfabric finishing materials, with a measured amount of volatile liquidammonia, for dispersing the nonvolatile material in the liquid ammoniaand for maintaining the proportion of such measured amount ofnonvolatile material in such measured amount of volatile liquid atsubstantially a constant level, the volatile liquid ammonia is first fedinto the insulated mixing vessel. A portion of the liquid ammoniavolatilizes and, with the coolant circulated through the coolant coilsin the insulated mixing vessel, lowers the temperature of the vessel andthe liquid ammonia therein. As such temperature is lowered, thevolatility of the liquid ammonia decreases and the level of the liquidammonia in the vessel increases. When the liquid ammonia reaches apredetermined level in the mixing tank and while continuing to feed suchliquid ammonia into the tank, a measured amount of the nonvolatilematerial is fed into the mixing tank, added to the liquid ammonia and,by agitating the liquid ammonia, is substantially uniformly dispersed ordistributed in the liquid ammonia in the mixing tank. While thenonvolatile material is being added and dispersed and continuing,thereafter, the feed of liquid ammonia to the mixing tank is continueduntil the level of the liquid ammonia in the mixing tank reaches themeasured amount. The feed of liquid ammonia to the mixing tank is thencut off but, as the liquid ammonia in the mixing tank volatilizes,additional liquid ammonia is added to the mixing tank to maintain theliquid level in the mixing tank at, substantially a constant level.

Agitation of the liquid ammonia and the nonvolatile material addedthereto in the mixing tank, and the addition of liquid ammonia to themixing tank to maintain the liquid level in such tank substantiallyconstant, continues until the liquid ammonia-additive mixture in thetank is to be used. During the addition of the liquid ammonianonvolatile material to the tank and while the material and liquid arebeing agitated, and additional liquid ammonia is being added to themixing tank to maintain the liquid level substantially constant, themixing tank is vented to an ammonia recovery system, an incineratorwhere the ammonia vapors are burned, or to the atmosphere.

When the liquid ammonia-additive mixture in the mixing tank is to be fedto the ammonia immersion trough 16 in the fabric treatment chamber 2,the feed of liquid ammonia to the mixing tank is cut off. The vent ofthe mixing tank containing the liquid ammoniaadditive mixture to be fed,is cut off from the ammonia recovery system, the incinerator or theatmosphere, as the case may be, and the mixing tank is then vented tofabric treatment chamber 2. Thus, the ammonia vapor saturated conditionof the atmosphere in the mixing vessel above the liquid ammonia-additivemixture in the mixing tank and the condition in the fabric treatmentchamber 2 are substantially the same and stabilized. The. liquidammonia-additive mixture charged mixing tank is thenon stream to feedliquid ammoniaadditive mixture to fabric immersion trough 11], theliquid ammonia-additive mixture in the charged mixing tank being fed totrough 10 as the level of the mixture in such trough drops.

In charging the mixing tank in accordance with the instant invention,manual switch 118 is opened, deenergizing solenoid 36, closing valve 34and deenergizing solenoid switch 116. Thus, micro-switch l 14 isconnected to the power supply, not shown. Because the mixing tank isthen empty, floats 112 and 102 are down. With float 112 down,micro-switch 114 is closed and energizes solenoid 110, opens valve 98and allows liquid ammonia from a source, not shown, to feed, throughliquid ammonia line 96, into mixing chamber 70. With float 102 in thedownposition, micro-switch 104 is open. Hence, timer 110 and solenoid 94are not energized. Valve 92 is closed and remains closed. No additive isfed into mixing chamber 70.

During the charging of the mixing tank, the tank being charged is ventedto duct 4. Thus, the flapper valve to duct 47 is open and closed to duct46, leading to chamber 2. When the tank is on stream, the flapper valvein the vent of the tank on stream is in the reverse position, i.e.,vents the charged, on stream tank to duct 46 leading to chamber 2 andcuts-off the vent to duct 47.

While the liquid ammonia is being fed to the tank undergoing charge,coolant is pumped through coolant coils 86. Coolant coils 86, and theliquid ammonia vaporizing in the tank undergoing charge rapidly lowerthe temperature in mixing chamber 70 so that, as the ammonia level risesin mixing chamber 70 and the temperature within mixing chamber 70 lowersvaporization of the ammonia in mixing chamber 70 decreases. Thus, theamount of ammonia vapor discharged into duct 47 and recovered, burned,or discharged in the atmosphere, decreases. As the liquid ammonia levelin mixing chamber 70 continues to rise, the ammonia level reaches float102, lifts the floats and closes microswitch 104. When micro-switch 104closes, timer 110 is actuated and energizes solenoid 94 and opens valve92. Additive, through additive supply line 90 is fed into mixing chamber70. Timer 110 is set so that solenoid 94 is energized for a fixed timeinterval. Thus, valve 92 remains open for a fixed time interval and ameasured amount of additive is fed, through supply line 90, into mixingchamber 70. At the end of the pre-set time interval, timer 110de-energizes solenoid 94 and closes valve 92.

While the liquid ammonia and additive are being fed into mixing chamber70, while the mixing chamber is charged and at stand-by and while thecharged mixing chamber is on stream, mixer 80 is in operation and mixerimpeller 84 continuously agitates the additive in the liquid ammonia,maintaining the additive dispersed in the liquid ammonia in mixingchamber 70.

During the addition of the additive to mixing chamber 70, throughadditive supply line 90 and open valve 92, liquid ammonia is beingcontinuously fed, through liquid ammonia supply line 96 and open valve98, into mixing chamber 70. When the liquid ammonia level in chamber 70reaches float 112, the liquid ammonia in mixing chamber 70 raises float112, opens microswitch 114, de-energizes solenoid 100 and closes valve98 cutting off further flow of liquid ammonia into mixing chamber 70.With the flow of liquid ammonia through feed line 96 cut off, the liquidammoniaadditive mixture in mixing chamber 70 is ready for use. However,at such time, the other mixing tank, previously charged and placed onstream, may not be empty. Thus, the more recently charged mixing tankmust be maintained at a hold condition with the properadditivc-to-liquid ammonia proportion and dispersion until such recentlycharged mixing tank is put on stream.

During such holding some of the liquid ammonia in the recently chargedmixing tank will vaporize depending, of course, upon the temperature ofthe mixture. The liquid ammonia in such mixture is volatile and theadditive is not. Thus, as the liquid ammonia vaporizes and the level inmixing chamber falls, with the mixing tank on hold, the additiveconcentration in the mixture will increase. To avoid such increase inadditive concentration and to maintain the additive-liquid ammonia, inthe mixing tank at the desired concentration, when the liquid level inmixing chamber 70 drops float 112 lowers, closes micro switch 114,re-energizes solenoid and re-opens valve 98. Thus, additional liquidammonia is fed into mixing chamber 70 until the liquid level againrises, raises float 112, recloses micro-switch 114, de-energizessolenoid 110 and recloses valve 98. Hence, the liquid level in mixingchamber 70, while the mixing tank is on hold, is maintained at asubstantially constant level.

The closing of switch 118, energizing of solenoid 36 and opening ofvalve 34, placing the charged mixing tank on stream opens valve 116 andde-energizes micro-switch 114 and solenoid 110. Thus, while the tank ison stream, further flow of liquid ammonia through feed line 96 into theon stream tank is cut off. While the tank is on stream, the tank isvented to chamber 2 through duct 46. Thus, ammonia vapor conditions inthe area above the ammonia in the tank that is on stream and the vaporconditions in chamber 2 are equalized and substantially the same.

The method and apparatus of the instant invention may be utilized in theammonia treatment of fabric where additive materials, in addition to theammonia, are employed in the fabric treatment. Thus, the apparatus andprocess may be employed for the addition of any material that iscompatible with liquid ammonia and can be dispersed therein.

In the foregoing description, two tanks have been described, one tankbeing on stream and the other tank being in the process of being chargedor charged and on hold while the first tank is on stream and beingemptied. It is to be understood that, in the operation of the instantapparatus and process, more than two tanks may be used. The use ofadditional tanks is of particular advantage where various fabrics are tobe treated, one fabric after the other, with ammonia and differentadditives, or the same additives in different proportions, such asresins in different proportions. I

The terms and expressions which have been employed are used as terms ofdescription and not of limitation, and there is no intention in the useof such terms and expressions of excluding any equivalents of thefeatures shown and described or portions thereof, but it is recognizedthat various modifications are possible.

What is claimed is:

1. Apparatus for mixing a measured amount of nonvolatile material with ameasured amount of volatile liquid and for maintaining the proportion ofsaid material in said liquid substantially constant, said apparatuscomprising a mixing tank having an insulated mixing chamber and a coverover said chamber, a coolant coil for circulating coolant in saidchamber, first feed means for feeding a volatile liquid into saidchamber, a valve in said first feed means, a second feed means forfeeding.-a nonvolatile material into said chamber, a

valve in said second feed means, a first float in said chamber, meansconnecting said first float to said valve in said first feed means, asecond float in said chamber, means connecting said second float to saidvalve in said second feed means, means for discharging the mixture ofsaid measured amount of nonvolatile material and said measured amount ofvolatile liquid from said mixing tank after said measured amounts havebeen mixed therein, valve means in said discharge means, means connectedto said valve means in said discharge means for opening and closing saiddischarge valve means, said means for opening and closing said dischargevalve means including means for opening said valve in said first feedmeans when said discharge valve means is closed and for closing saidvalve in said first feed means when said discharge valve means isopened, said first float in said chamber including means for closingsaid valve in said first feed means when the liquid in said chamberlifts said first float and for opening said valve in said first feedmeans when the liquid in said chamber is below the level to lift saidfloat.

2. Apparatus, as recited in claim 1, in which said means connecting saidsecond float to said valve in said second feed means includes a timerand means for actuating said timer and for opening said valve in saidsecond feed means when the liquid in said chamber lifts said secondfloat, said timer including means for closing said valve in said secondfeed means after a predetermined timed interval.

3. Apparatus, as recited in claim 2, including a fabric treatmentchamber, a trough in said chamber, means connecting said means fordischarging said mixture from said mixing tank to said trough, valvemeans in said last mentioned connecting means, third float means on saidtrough and means connected to said third float for closing said lastmentioned valve means when liquid in said trough lifts said third floatand for opening said last mentioned valve means when the liquid in saidtrough is below the level to lift said third float.

4. Apparatus, as recited in claim 3, in which said cover includes ventmeans, means for connecting said vent means on said cover to vapordischarge means when said nonvolatile material and said liquid are beingfed to and mixed in said mixing chamber and for connecting said vent tosaid fabric treatment chamber when said mixture from said mixing tank isbeing discharged to said trough.

5. Apparatus for mixing a measured amount of nonvolatile material with ameasured amount of volatile liquid and for maintaining the proportion ofsaid material in said liquid substantially constant and for dischargingand feeding the mixture of nonvolatile material and volatile liquid to atreatment trough in a fabric treatment chamber, said apparatuscomprising a plurality of mixing tanks each having an insulated mixingchamber and a cover over said chamber, a coolant coil in each of saidtanks for circulating coolant in said chamber, first feed means in eachof said tanks for feeding a volatile liquid into said chamber of saidmixing tank, a valve in each of said first feed means, a second feedmeans in each of said tanks for feeding a nonvolatile material into saidchamber of said tank, a valve in said second feed means. a first floatmeans in each of said chambers, means connecting said first float meansin each of said chambers to said valve in said first feed means, asecond float in each of said chambers, means connecting said secondfloat to said valve in said second feed means, a fabric treatmentchamber,

a trough in said chamber, means connected to said trough and to each ofsaid mixing tanks for discharging the mixture of said measured amount ofnonvolatile material and said measured amount of volatile liquid fromeach of said mixing tanks and for feeding said mixture to said trough,valve means in said discharge connection means of each of said mixingtanks, means connected to said valve means in said discharge connectionmeans of each of said mixing tanks for opening and closing said valvemeans in said discharge connection means in each of said tanks includingmeans for opening said valve in said first feed means in said tank whensaid valve means in said discharge connection means in said tank isclosed and for closing said valve in said first feed means in said tankwhen said valve means in said discharge connection means in said tank isopened, said first float means in each of said chambers including meansfor closing said valve in said first feed means in said tank when theliquid in said chamber in said tank lifts said first float and foropening said valve in said first feed means in said tank when the liquidin said chamber in said tank is below the level to lift said float.

6. Apparatus. as recited in claim 5, in which said means connecting saidsecond float to said valve in said second feed means includes a timerand means for actuating said timer and for opening said valve in saidsecond feed means when the liquid in said chamber lifts said secondfloat, said timer including means for closing said valve in said secondfeed means after a predetermined time interval.

7. Apparatus, as recited in claim 6, in which said means connected tosaid trough and to each of said mixing tanks for discharging saidmixture to said trough includes valve means, third float means on saidtrough and means connected to said third float for closing said lastmentioned valve means when liquid in said trough lifts said third floatand for opening said last mentioned valve means when the liquid in saidtrough is below the level to lift said third float.

8. Apparatus, as recited in claim 7, in which said cover on each of saidmixing tanks includes vent means, means for connecting said vent meanson each said cover to vapor discharge means when said nonvolatilematerial and said liquid are being fed to and mixed in the mixingchamber of said mixing tank and for con necting said vent to said fabrictreatment chamber when said mixture from said mixing tank is beingdischarged to said trough.

9. Apparatus for mixing a measured amount of nonvolatile material with ameasured amount of volatile liquid and for maintaining the proportion ofsaid material in said liquid substantially constant, said apparatuscomprising a mixing tank having a mixing chamber and a cover over saidchamber, first feed means for feeding a volatile liquid into saidchamber, a valve in said first feed means, a second feed means forfeeding nonvolatile material into said chamber, a valve in said secondfeed means, a first float in said chamber, means connecting said firstfloat to said valve in said first feed means, a second float in saidchamber, means connecting said second float to said valve in said secondfeed means, means for discharging the mixture of said measured amount ofnonvolatile material and said measured amount of volatile liquid fromsaid mixing tank after said measured amounts have been mixed therein.valve means in said discharge means, means connected chamber includingmeans for closing said valve in said first feed means when the liquid insaid chamber lifts said first float and for opening said valve in saidfirst feed means when the liquid in said chamber is below the level tolift said float.

1. Apparatus for mixing a measured amount of nonvolatile material with ameasured amount of volatile liquid and for maintaining the proportion ofsaid material in said liquid substantially constant, said apparatuscomprising a mixing tank having an insulated mixing chamber and a coverover said chamber, a coolant coil for circulating coolant in saidchamber, first feed means for feeding a volatile liquid into saidchamber, a valve in said first feed means, a second feed means forfeeding a nonvolatile material into said chamber, a valve in said secondfeed means, a first float in said chamber, means connecting said firstfloat to said valve in said first feed means, a second float in saidchamber, means connecting said second float to said valve in said secondfeed means, means for discharging the mixture of said measured amount ofnonvolatile material and said measured amount of volatile liquid fromsaid mixing tank after said measured amounts have been mixed therein,valve means in said discharge means, means connected to said valve meansin said discharge means for opening and closing said discharge valvemeans, said means for opening and closing said discharge valve meansincluding means for opening said valve in said first feed means whensaid discharge valve means is closed and for closing said valve in saidfirst feed means when said discharge valve means is opened, said firstfloat in said chamber including means for closing said valve in saidfirst feed means when the liquid in said chamber lifts said first floatand for opening said valve in said first feed means when the liquid insaid chamber is below the level to lift said float.
 2. Apparatus, asrecited in claim 1, in which said means connecting said second float tosaid valve in said second feed means includes a timer and means foractuating said timer and for opening said valve in said second feedmeans When the liquid in said chamber lifts said second float, saidtimer including means for closing said valve in said second feed meansafter a predetermined timed interval.
 3. Apparatus, as recited in claim2, including a fabric treatment chamber, a trough in said chamber, meansconnecting said means for discharging said mixture from said mixing tankto said trough, valve means in said last mentioned connecting means,third float means on said trough and means connected to said third floatfor closing said last mentioned valve means when liquid in said troughlifts said third float and for opening said last mentioned valve meanswhen the liquid in said trough is below the level to lift said thirdfloat.
 4. Apparatus, as recited in claim 3, in which said cover includesvent means, means for connecting said vent means on said cover to vapordischarge means when said nonvolatile material and said liquid are beingfed to and mixed in said mixing chamber and for connecting said vent tosaid fabric treatment chamber when said mixture from said mixing tank isbeing discharged to said trough.
 5. Apparatus for mixing a measuredamount of nonvolatile material with a measured amount of volatile liquidand for maintaining the proportion of said material in said liquidsubstantially constant and for discharging and feeding the mixture ofnonvolatile material and volatile liquid to a treatment trough in afabric treatment chamber, said apparatus comprising a plurality ofmixing tanks each having an insulated mixing chamber and a cover oversaid chamber, a coolant coil in each of said tanks for circulatingcoolant in said chamber, first feed means in each of said tanks forfeeding a volatile liquid into said chamber of said mixing tank, a valvein each of said first feed means, a second feed means in each of saidtanks for feeding a nonvolatile material into said chamber of said tank,a valve in said second feed means, a first float means in each of saidchambers, means connecting said first float means in each of saidchambers to said valve in said first feed means, a second float in eachof said chambers, means connecting said second float to said valve insaid second feed means, a fabric treatment chamber, a trough in saidchamber, means connected to said trough and to each of said mixing tanksfor discharging the mixture of said measured amount of nonvolatilematerial and said measured amount of volatile liquid from each of saidmixing tanks and for feeding said mixture to said trough, valve means insaid discharge connection means of each of said mixing tanks, meansconnected to said valve means in said discharge connection means of eachof said mixing tanks for opening and closing said valve means in saiddischarge connection means in each of said tanks including means foropening said valve in said first feed means in said tank when said valvemeans in said discharge connection means in said tank is closed and forclosing said valve in said first feed means in said tank when said valvemeans in said discharge connection means in said tank is opened, saidfirst float means in each of said chambers including means for closingsaid valve in said first feed means in said tank when the liquid in saidchamber in said tank lifts said first float and for opening said valvein said first feed means in said tank when the liquid in said chamber insaid tank is below the level to lift said float.
 6. Apparatus, asrecited in claim 5, in which said means connecting said second float tosaid valve in said second feed means includes a timer and means foractuating said timer and for opening said valve in said second feedmeans when the liquid in said chamber lifts said second float, saidtimer including means for closing said valve in said second feed meansafter a predetermined time interval.
 7. Apparatus, as recited in claim6, in which said means connected to said trough and to each of saidmixing tanks for discharging said mixture to said trough includes valvemeans, third float meAns on said trough and means connected to saidthird float for closing said last mentioned valve means when liquid insaid trough lifts said third float and for opening said last mentionedvalve means when the liquid in said trough is below the level to liftsaid third float.
 8. Apparatus, as recited in claim 7, in which saidcover on each of said mixing tanks includes vent means, means forconnecting said vent means on each said cover to vapor discharge meanswhen said nonvolatile material and said liquid are being fed to andmixed in the mixing chamber of said mixing tank and for connecting saidvent to said fabric treatment chamber when said mixture from said mixingtank is being discharged to said trough.
 9. Apparatus for mixing ameasured amount of nonvolatile material with a measured amount ofvolatile liquid and for maintaining the proportion of said material insaid liquid substantially constant, said apparatus comprising a mixingtank having a mixing chamber and a cover over said chamber, first feedmeans for feeding a volatile liquid into said chamber, a valve in saidfirst feed means, a second feed means for feeding nonvolatile materialinto said chamber, a valve in said second feed means, a first float insaid chamber, means connecting said first float to said valve in saidfirst feed means, a second float in said chamber, means connecting saidsecond float to said valve in said second feed means, means fordischarging the mixture of said measured amount of nonvolatile materialand said measured amount of volatile liquid from said mixing tank aftersaid measured amounts have been mixed therein, valve means in saiddischarge means, means connected to said valve means in said dischargemeans for opening and closing said discharge valve means, said means foropening and closing said discharge valve means including means foropening said valve in said first feed means when said discharge valvemeans is closed and for closing said valve in said first feed means whensaid discharge valve means is opened, said first float in said chamberincluding means for closing said valve in said first feed means when theliquid in said chamber lifts said first float and for opening said valvein said first feed means when the liquid in said chamber is below thelevel to lift said float.